Fluid coupling



W. F. MITCHELL FLUID COUPLING May 19, 1953 4 Sheets-Sheet 1 Filed Dec. 13, 1950 zz/Qzzace May 19, 1953 w. F. MITCHELL FLUID COUPLING 4 Sheets-Sheet 3 Filed D90. 13, 1950 QN mm NW 6% g wwws WWN W. F. MITCHELL FLUID COUPLING 4 Sheets-Sheet 4 Filed Dec. 13, 1950 I I i I iNVENTOR.

determined position.

Patented May 19, 1953 2,638,915 1 FLUID COUPLIIQ'G Wallace of Illinois M ichfi ca 1 ass gnqr to G, Coipo'ration, Chicago, 111;, a corporation ApplicationDeceniber 13, 1950, Serial No 3200;659

-ma tica11y at least one set of corresponding sections of the conduits.

Many hydraulic control systems for example; as are used tor remote control ot the operation of tractor-drawn apparatus, such as earth working or farm implei'n'ents v are provided with self sealing breakaway couplings. such systems customarily embody two cohau tseach formed. in tWo sections connected respectively to the fluid pressure source; usually mounted on their-actor, and t o the fluid pressure actuated motor mounted on the implement, implement is usually connected to the tr tor by a traction connection adapted to separate upon the application oi an unusual force thereto, such as occurs when the implement encounters an unusual obstruction anol tlie breakaway couplings permit concurrent separation of the coupling sections to prevent damage to the connected apparatus.

Moreover, systems of the aforesaid was often include a pressure operated notor'oa ied on the tractor for actuating an implement cai rid on or connected directly to the tractor, ,or

for other purposesWhen it is de'sirejd to utilize the force available in the hydraulic ystem.

Such a tractor mounted motor is serially connected in the hydraulic system between the fluid pressure maintaining apparatusand the breaks way coupling. separated the system is effectivelybio'cketli and thus prevents operation of the tractor mounted 7 motor.

coupling which are to be connected to oneset of; fluid; conduitsare rigidly secured together whereby the coupling may bercadily supported with the separable portions maintained in pre- A further object is Hence, when the cou ling is to provide a multiple self-- t 2 ling b eakawa ins i n .a 'at iri eoop'racirig sections a: each eta] p1 1- rality of {conduits and, adaptedto permit L racer; sf the soc-permits estimates can tit ecti s an 1 1 9 uchssenarati n 1 E84 t ends; or an or the conduit section's and at the same t me. inte ciicn qtt r espqn iee ciidiiii sections and tlierliy'interconiiect the several conduits.

a s, i i itbj ip e ai e:-

sealing was unit-rot aver ges 5.3 9%61 v 9 the 7 a 1 11 i i .1 ia i iqdvf J v; Q dbv uid conduits; winch couplin unit permits autom tic separation of the fluid conduits and consequent cassettes 6r of the and wlilc 1s fis s an m (18,113? to irite'rc ne'ct ofr're mafia-g aids or t separatdcoiidu to m in a era ed swarms use in atlast one the system despite sues separation uits.

Another object is to provide a simmers saisealing breakaway coupling unit for cone it settionsjin a Hydraulic system,

f aratioh or the conduit para-ted enas ar'id at the are bypass the fluidaround the" source V "e se estamisn a closed circuit ts tii may vent tri; application of excessive fluid pressure is are system.

Another object of the invention is to provide a multiple breakaway coupling unit which is strong-ans mggsa; simple in construction and operaticin; andefiective inaction;

A further object is to provide a breakaway eoupii' having a novel protective' c'as-ing adapted to enclose the" end or the female coupling sect'iojri' wlieri the coupling is in uncoupled coriamen afiii thereby prevent the entry of dirt and of "er foreign matter into the female section.

ot erobjcts and aii'vantage's of the inventio r11 ap majors following description taken connection with tl'feapp'erided drawin g s x'yliiein'z" Fig ur i a uifiit 2 3 trative application of the coupling unit of Fig. 1 (the coupling unit being shown as being rotated about its horizontal center line 90 from its usual position, for convenience in illustration);

Fig. 5 is an enlarged horizontal longitudinal sectional view taken through the coupling unit of Fig. 1 showing the coupling sections separated with the complementary parts thereof poised for coupling operation;

Fig. 6 is an enlarged vertical longitudinal sectional view taken substantially along the line 66 of Fig. 1;

Fig. '7 is a horizontal longitudinal sectional view taken substantially along the line 1-1 of Fig. 3;

Fig. 8 is a transverse sectional view taken substantially along the line 8-8 of Fig. 5;

Fig. 9 is a top plan view of the twin section of a coupling unit generally similar to that shown in Fig. 1 showing a dust cover associated therewith;

Fig. 10 is a front elevational view of the device of Fig. 9;

Fig. 11 is a side elevational view of the device of Fig. 9;

Fig. 12 is a vertical sectional view taken along the line I2l2 of Fig. 9;

Fig. 13 is a horizontal sectional View through the right hand portion of the device of Fig. 9 with the dust cover flap open; and

Fig. 14 is a view generally similar to Fig, 13 but showing the complete coupling in coupled condition.

Although the present invention is capable of many uses, some of which have been briefly outlined previously, it has been illustrated in connection with a hydraulic system associated with tractor-drawn farm implements wherein the earth engaging portions of the implement are hydraulically controlled from the tractor by the operator.

The coupling unit of the present invention is illustrated as a twin unit adapted to connect the cooperating conduit sections of two conduits as the invention finds its principal application in such form. However, the invention is not limited to a coupling for connecting the sections of only two conduits but may, with suitable modification, be designed to connect the sections of a greater number of conduits.

Before entering into a detailed description of the specific mechanism of the coupling unit, reference will first be made to the device in a general way and to one particular application of the invention in order that the detailed structure to be later described will be more readily understood. For this purpose attention is directed first to Figs. 1 to 4 inclusive showing the exterior of the device and its inclusion in a hydraulic system. The twin coupling unit H) is adapted for coupling fluid conduit sections [2 and I4 together in asingle fluid conduit and similarly conduit sections l6 and 18 together in another fluid conduit. A tractor 20 represented diagrammatically in Fig. 4 includes a hydraulic fluid storage tank 22 having a fluid conduit 24 in which is interposed a pump 26 which may be a conventional gear pump. The conduit 24 then leads to a control valve 23 from which the conduit section l2 referred to above leads. The conduit section [4 on the opposite side of the coupling unit communicates With a fluid motor 30 which, in the present instance, includes a cylinder 3| having a piston 32 slidable therein and connected toa connecting 4 rod 34. Leading from the cylinder 3| on the opposite side of the piston is the conduit section I8 referred to above, connected through the coupling unit ill to the fluid section 16, the latter communicating with another fluid motor 36 which may be similar to the motor 38. Leading from the cylinder of the motor 36 on the side of the piston 32 opposite the rod 34 is another fluid conduit 38 which communicates with the control valve 28. Another fluid conduit 40 communicates between the control valve 28 and the storage tank 22 to complete the hydraulic system. The

, control valve 28 is provided with well known valve means which can be operated by a control handle 42 for reversing the flow of fluid alternately through the conduits l2 and 38 and thereby alternately reversing the action of the hydraulic motors 30 and 36.

The tractor 20 may be employed for pulling a vehicle such as a farm implement or other earth working implement and the hydraulic motor 30 is utilized for actuating the movable parts on the drawn vehicle while the hydraulic motor 36 may be utilized for operating other devices mounted on the tractor. As is Well known, a drawn vehicle may encounter an unusual obstruction and become detached from the tractor and in such case of course it is highly desirable that the fluid conduits of the hydraulic system be disconnected without damage thereto. To this end the coupling unit i0 is constructed so that the conduit sections l4 and I8 will readily part or break away from the coupling unit Ill without damage to any part of the hydraulic system.

It will be noted that the hydraulic motors 30 and 36 are connected in series, that is, they are interconnected on respectively opposite sides of the pistons therein through the fluid conduit I6, [8, the fluid in that conduit flowing from one motor to the other depending upon the direction of movement of the pistons in the motors at the time. If the motor 30 and the conduit sections l4 and I8 should be disconnected or broken away from the remainder of the system, and the conduit sections 12 and I6 are closed by the selfclosing valve means provided therefor, fluid pressure would build upin the conduit sections l2 and 16 with consequent damage to the system, if means were not provided for preventing such build-up of pressure. The present invention includes means, to be described later in detail, for interconnecting the conduit sections l2 and I6 through the coupling unit In when the conduit sections I 4 and I8 are disconnected from the coupling unit, thereby establishing a complete circuit in that portion of the hydraulic system remaining on the tractor. However when the conduit sections 54 and l 8 are connected to the coupling unit, communication between the conduit sections I2 and I6 is blocked, and both fluid motors are connected in the hydraulic system in the manner above described.

Referring now in detail to the structure of the coupling unit, the unit includes a block 44 (Fig. l) which may be a casting, having laterally spaced tubular portions 46 defining bores 48 (Fig. 5) extending therethrough. The tubular portions 46 are interconnected by a transverse piece 50 in which is formed another bore 52 which may be referred to as a transverse passage or bypass and which interconnects bores 48. A reinforcing web 54 may also interconnect the tubular portions. The block Ill preferably is provided with an eye portion 56 to receive a pin or bolt 58 for mounting the block and thereby the coupling un'it on' the tractor or other intended place. Atten'tio'n is called to the fact at this point that the block forms the mounting means for the coupling unit and the block is fixedly mounted in position whereby other elements of the unit move relative to the block and cause the fluid conduit sections to be disconnected.

Each of the two 'QUJJES' E-E of the block adapt ed for mounting a pair of cooperating coupling sections 59 and Bi) which, together with the corresponding portion of the block l lyfcrm a sin e coupling which constitutes one part of the t-v-n coupling unit. Each of the single couplings here in disclosed is similar in certain respects to and embodies contain novel features of the coupling disclosed and claimed in my applicw tion Serial No. 95,553 filed May 26, 1.94.9. The cooperating coupling sections in each bore (it identical with those in the other, and the fol lowing specific description with reference to one of them'will be understood to loo-equally applicable to the other.

Slidably mounted in the bore 42% is a tubular member 6! extending out each end of the and having a bore t2 interiorly threaded at one end as at 63 for reception of a rig-id end-fitting 64 on'the conduit section it (or iii). The forward end of the tubular member iii-l is provided with an enlarged head 56 having a radially extending portion 51 and a circumferential flange 68 forming a socket Iii which is of enlarged diameter relative to the diameter of the remainder of the tubular portion. A compression spring 72 surrounds the tubular member Si at the rear end, compressed between theadjacent of the block M and a cup M fitted on the tubular member and held in placethereon by a split ring it fitted in a groove in the tubular member. The spring l2 urges the tubular member to the left or retracted position 5) wherein the head the adjacent end of the block id. In movement of the tubular member 5! in the opposite direction, for a purpose to be described later. the cup M will engage the block before the spring 72 is fully compressed and thereby serve as a stop means so as to relieve the spring of that function.

The tubular member iii is provided with a plurality of radial valve ports .73 establishing con1- munication between the interior of the tubular member and the bore 48 and when the tubular member is in retracted position the valve ports 1.8 are in communication with the transverse pasage 52 both directly and through a circumfer-= ential groove or passage 36 in the bore it and forming a continuation of the transverse passage 52. Circular sealing rings 82 and t l or 0 rings are fitted in annular grooves it and 8? respectively on opposite sides oi the passage 3% for seal the tubular member ti. The ring 82 fur nishes a seal against the escape of fluid from the bore d8 to the exterior and. the ring 34 furnishes a seal against the escape of fluid from the ports it into passages it and when the tubular member is in advanced position as will be referred to later. Another circular sealing ring 3% or Q ring is position-ed in a groove 32 in the exterior surface or the tubular member ti for sealing the device against escape of fluid from the here ts to the exterior in the opposite direction.

Adjacent the forward end of the bore 62 is inwardly extending flange or. for mounting a circular valve seat 98 for a valve member 98 which closesand seals the corresponding end of the bore '62 when the sections of the coupling unit are separated. The valve member 98 slidably mounted in the bore t2 and includes anchem ended cylindrical tubular portion we, a reduced portion 1 02 having valve ports 'I M communicating between-the interior-of the valve member and the bore 52', and-aseating surface 1% adapted-t0 encage the valve seat 9E, and finally a forwardly extending projection 108 which p-rojeets beyond the flange 94 in the positionshown in Fig.5. The valve member 98 is urged to'closed position shown in 5 by a compression spring HEB extending into the valve memberand seated at the opposite end-against anannular spring-seat l-H supported by a split ring H2 fitted in a circumferential groove in the here 132. The seat Hi furnishes-a stop for lin'iiting movement of the valve to retracted or'openposition. When thecoupling sec? tions are disconnected, the valve 93 is automatztmoved to closed position (Fig. 5) for sealing the fluid line section l2 against the escape of fluid. It is moved to open position by the move ment 20f the coupling sections together in the coupling operation, as will be described hereinafter.

.Forwardly of the flange 94 is a sealing ring H3 positioned in a groove III! in the bore of the tubular member (ii, for sealingly engaging the coupling unit fill. This sealing action will be described in detail later.

A pairof axially extending locking and stop pins 1 15 are fixedly secured in holes in the forward end of the block adjacent the bore t8 and. extend forwardly through holes H1 in the radially extending portion 6! of the hE/ftd. into the socket ill. The pins Mil have a slit-ling fit in the holes i ii and thereby prevent rotation of the coupling section 59 but at the same time permit free movement of the section 59 in an axial direction. forward ends of: the stop pins have reduced extensions I it forming shoulders H8. The flange 58 is provided with diametrically opposite arcuate slots i2!) inclined with respect to both the axis of the tubular member and a line perpendicular thereto in progressively varying extent and in all parts thereof inclined with vrespect to the W0 lines mentioned, i. e.,, no part of the slots is parallel with the axis of the tubular member or with a line perpendicular thereto. The slots l'll'il form cam surfaces for cooperation with camming elements on the coupling section 68' now to be described in detail.

The coupling section til includes a tubular member I22 having a bore I211 interiorly threaded for receiving an end-fitting I M connected to the conduit section M (or i8). The tubular portion I22 includes a portion lZt of reduced diameter and a portion ltll of enlarged diameter, the latter forming a shoulder I32 in which are formed recesses or sockets 134 adapted for receiving the extensions M6 on the stop pins H5 when the coupling sections are coupled. The extended and of the reduced portion I28 has a turned-in flange or head H36 for mounting a circular valve seat i313. Slidably mounted in the here i124 is a: valve member Mil similar in all respects to the valve member 98 and effective for engaging the valve seat 38 for closing the" bore lit and thereby the line section is when the coupling sections are separated. The valve Mil is provided with an extension It; engageable with the extension i138 on the valve member ill? when the coupling sections are coupled. Radially extending holding and camrning studs l M are secured in the portion 822 of the coupling section 69 for insert-ion into and cooperation with the cam slots 29 for coupling the sections.

When the coupling sections are disconnected,

as shown in Fig. 5, the valve members I40 and 98 are efiective for automatically closing the respective conduit sections so that none of the fluid escapes from the hydraulic system. Attention is directed to Figs. 5, 6 and 7 in connection with the following discussion of the method of coupling the coupling sections. Coupling section 60 is moved to the left from the position shown in Fig. 5 and. inserted into the socket ID in such angular position that the camming studs I44 enter the cam slots I29. The coupling section 60 is then rotated and, through the interaction of the cam slots I20 and camming studs I44, the coupling section is moved axially into the socket. The axial movement of the coupling section into the socket causes the face I32 to engage the stop pins I I5 and prevents further relative axial movement between the coupling section and the block 44 and, as a consequence, relative movement between the coupling section 60 and the head 66 causes the latter to move outwardly relative to the block against the action of the compression spring I2. This obviously results in the movement of the tubular member (H to the right from the retracted position of Fig. 5 to the advanced position of Figs. 6 and '7.

When the coupling section 60 is rotated fully so that the camming studs I44 are at the innermost ends of the cam slots (Fig. 1) the recesses I34 are in position to receive the ends I I6 of the stop pins II5, the latter actionpermitting the tubular member 6i and the coupling section 60 together to move as a unit slightly to the left under the action of the spring I2.

Owing to the coaction of the studs I44 and the edges of the seats I29, the coupling section 60 can be removed from the socket I only by rotational movement relative to the section 59. That is to say, axial thrust of the coupling unit Without rotational movement thereof will result only in the axial thrust being imparted as such to the head 66. Therefore, so long as the pins II are retained in the sockets I34 the coupling section 60 is held against rotational movement, and the coupling section is effectively connected to the head 66 and thereby with the coupling section 59. The compression spring 172 urges the tubular member 6| to the retracted position, and therefore urges the coupling section 69 to the left when it is coupled to the head 66, and consequently normally retains the pins I I5 in the recesses. In this condition of the coupling the pins hold the coupling section 60 in spaced relation to the block, and thereby the head 66 in similar spaced relation, and additionally retain the coupling section against rotation. To disconnect the coupling sections 59 and ISO, the coupling section 60 is drawn to the right until the pins I I5 are withdrawn from the recesses I34, after which rotation of the coupling section is permitted.

In the coupling action the valve members 98 and I40 interengage through their respective extensions ID8 and I42 and mutually unseat each other as shown in Figs. 6 and 7. The valves are opened simultaneously or sequentially depending upon fluid pressure conditions in the couplings. For example, if pressure exists in the bore 62, but not in the bore I24, the valve member 83 is retained in closed position until the valve I 48 opens and reaches its limit stop, whereupon the valve member 98 then opens establishing communication between the bores 62 and I24 and thereby between the fluid line sections I2 and I4 (or I6 and I8).

It will be noted that the sealing ring II3 engages the reduced portion I28 of the coupling section 60 and prevents the escape of fluid to the exterior of the device in that direction during coupling and uncoupling. Thus, the coupling is sealed during coupling, prior to the opening of the valves, and conversely, is sealed during uncoupling until after the valves close.

It will be noted from Figs. 6 and '7 that when the coupling sections are coupled and the tubular member 6| is in advanced position, the valve ports I8 are disposed inwardly of the sealing ring 84 which blocks communication between the bore 62 and the transverse passage 52, thereby preventing communication between the companion fluid lines passing through the twin coupling unit. At this point reference is again made to Fig. 4 and from the above description it will be obvious that when the conduit sections I4 and I8 are connected in the coupling unit the hydraulic system is established in a series arrangement through the two hydraulic motors.

If the implement on which the hydraulic motor 30 is mounted should be disconnected from the tractor and, as a consequence, the conduit sections I4 and I8 be subjected to undue pulling force, the coupling sections 60 on the conduit sections I4 and I8 will immediately be detached from the twin coupling unit. The action is as follows. It will be recalled that each coupling section must be rotated in order to be detached from the respective socket I9 and in normal conditions the pins I I5 prevent rotation of the coupling section because a locking effect is established by the spring I2 by which the ends II6 of the pins are retained in the recesses I34. However, when undue pulling force is exerted on a line section such as I4, the force will draw both the coupling section 611 and the tubular member 6| to the right (as viewed in Fig. l for example) against the action of the spring I2, this being efiected by reason of the fact that the thrust of the camming studs I44 is directed axially as long as the pins II5 are in the recesses I34, as explained above. The force continues until the ends II6 of the locking pins are withdrawn from the recesses, after which rotation of the coupling section is permitted due to the pulling force and the camming action between the camming studs and the cam slots.

After the coupling sections are disconnected from the respective sockets the tubular members 6| are moved by their respective springs to retracted position (Fig. 5) in which the valve ports I8 are in communication with the transverse passage 52, establishing direct communication between the bores 62 of the companion lines through the coupling unit and thereby between the conduit sections I2 and I6 (Fig. 4) whereby a complete circuit is established through the single hydraulic motor 38. It will be understood that when the line sections I4 and I8 are separated, the valve members 98 are automatically moved to closed positions, closing the conduit sections I2 and I6.

As noted above, the block 44 is mounted in fixed position. As a result, any pulling force exerted on the conduit sections I4 and I3 causes relative movement between the coupling sections 59 and 60 and the block permitting disconnection of the coupling sections.

Attention is now directed to Figs. 9 to 14 inclusive showing a portion of a twin coupling unit of the type described above, having a dust cover applied thereto. The coupling unit portion in the present instance includes a block I46 similar ving member and maintained in closing condition in response to coupled condition of the sections of the respective coupling.

5. A multiple coupling unit for fluid conduits comprising a plurality of self-sealing breakaway couplings, each coupling including a pair of cooperating sections, each section having a fluid passage therethrough and being adapted for connection with a fluid conduit for placing its passage in communication with the conduit, means detachably connecting the sections of each pair together and thereby placing the passages therein in intercommunication, each section also having self-closing valve means for closing the passage therein when the sections of the coupling are separated, a unitary member supporting corresponding ones of the sections of the couplings and forming a portion of each such coupling, said unitary member defining a fluid passage interconnecting the passages in the sections supported thereby when the sections of each coupling are separated, and second valve means in each of the sections supported by said supporting member for closing the passage in the supporting member, said self-closing valve means being moved to open position and said second valve means being moved to closed position simultaneously in response to the coupling movement of the sections of the respective coupling.

6. A multiple coupling unit for fluid conduits comprising a supporting member having a plurality of bores therethrough and a transverse passage connecting said bores, a coupling section in each bore and having a fluid passage therethrough, each coupling section being slidable between a first position wherein the fluid passage therein communicates with the transverse passage and a second position in which said communication is blocked, a second coupling section having a passage therethrough cooperable with each of said first coupling sections, each pair of cooperable coupling sections forming a coupling adapted for connection with conduits, means for releasably interlocking the cooperable sections of each said pair in coupled position and maintaining the said first section thereof in its second position, means yieldingly maintaining each locking means in looking position and effective to urge each first section toward its first positionwhen the sections of each said pair are uncoupled, and self-closing valve means in each section for closing the passage therein when the coupling sections of the respective pairs are uncoupled.

7. A hydraulic coupling unit comprising a block having a pair of bores extending therethrough .and a passage establishing communication between the bores, a pair of couplings associated 'with respective bores and each including an open-ended tubular valve body slidably disposed in a respective bore and having a port formed intermediate its ends, an enlarged head formed on one end of the valve body with an arcuate cam surface thereon and positioned exteriorly of the block, said head having a socket therein for reception of a coupling section, spring means normally urging the valve body to a retracted position wherein the head thereon engages said block and the port therein is in communication with said passage, a thrust pin carried on said block and extending through each head and into the socket therein, a pair of coupling sections each comprising a tubular body and having a cam finger, said tubular body being adapted to be inserted into the socket in the respective valve body and upon rotation thereof in the socket to engage the respective thrust pin and by a camming action between the cam finger and arcuate cam surface draw the valve body from its retracted position to an advanced position wherein its port moves out of communication with said passage.

8. A hydraulic coupling unit comprising a block having a pair of bores extending therethrough and a passage establishing communication between the bores, a pair of couplings associated with respective bores and each including an open-ended tubular valve body slidably disposed in a respective bore and having a port formed intermediate its ends, an enlarged head formed on one end Of the valve body with an arcuate cam surface thereon and positioned exteriorly of the block, said head having a socket therein for reception of a coupling section, spring means normally urging the valve body to a retracted position wherein the head thereon engages said block and the port therein is in communication with said passage, a thrust pin carried on said block and extending through each head and into the socket therein, a pair of coupling sections each comprising a tubular body and having a cam finger, said tubular body being adapted to be inserted into the socket in the respective valve body and upon rotation thereof in the socket to engage the respective thrust pin and by a camming action between the cam finger and arcuate cam surface draw the valve body from its retracted position to an advanced position wherein its port moves out of communication with said passage, the end face of the tubular body having a locking recess for reception of the end of the respective thrust pin when the valve body and tubular body are coupled to lock them against relative turning movement.

WALLACE F. MITCHELL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 488,717 Pettet Dec. 27, 1892 515,220 Harris et a1 Feb. 20, 1894 2,043,337 Smith June 9, 1936 2,509,444 Mitchell May 30, 1950 2,538,259 Merriman Jan. 16, 1951 

